A. Field of the Invention
The present invention relates to a process for making portioned cheese, in particular fresh unripe cheeses, such as White Cheese, Feta, Cream Cheese, Cheddar and cottage cheese.
B. Description of the Prior Art
When cheese is manufactured according to the classic method the starting material is usually cow's milk or goat's milk, which may be homogenized. The milk may be used as whole milk, i.e. with its total solids content, or a major or minor portion of the cream may be centrifuged off.
The milk is coagulated by addition of rennet, and the coagulum is processed into cheese in several processing steps, comprising filtration of the separated whey, pressing in moulds and ripening or storage of the pressed cheeses. Sometimes the coagulum is also cooked and washed.
Instead of coagulating the milk by addition of rennet it is known to effect acidification, either by addition of a lactic acid forming bacterial culture or an inorganic acid, such as phosphoric acid, or an organic acid, e.g. lactic acid or gluconic acid. Also a neutral acidogen may be added, such as glucono-delta-lactone which releases gluconic acid by hydrolysis, cf. U.S. Pat. Nos. 2,982,654 and 3,620,768.
Addition of acid to a pH below about 5.0 usually causes instantaneous coagulation of the proteins in the milk.
It is known to replace the whole milk or skim milk starting material in the cheese making by a milk concentrate formed by ultrafiltration or diafiltration of the milk. Whole milk has a solids content of about 12%, of which about 3.5% is protein, about 3.5% is fat and the balance is lactose, minerals and small amounts of other substances, such as vitamins, etc. Ultrafiltration causes removal of a large portion of the water and the low-molecular substances, in particular the lactose and minerals, dissolved in the water. In retentate with a concentration of 35 to 40% solids constitutes a liquid cheese milk, which is processed into cheese in the usual manner by coagulation of the protein, recovery of the coagulum, pressing and subsequent treatment in the usual manner.
The described method of making cheese is very time-consuming and laborious. It is moreover uneconomical in that a considerable portion of the solids of the milk is lost, e.g. by low fermentation processes, or occurs in by-products of low commercial value.